Communication about multiple sclerosis (MS) disease progression between healthcare professionals (HCPs) and people with MS (PwMS) has historically been considered difficult, and attention to improving it has been neglected. However, a growing number of studies have shown that this is a key area to get right, since negative experiences can affect patient satisfaction, treatment adherence, and clinical outcomes. This article reports on a symposium at the European Charcot Foundation, 2018, led by a panel of leading clinicians and patient experts from MS in the 21st Century, who debated the benefits, drawbacks, and challenges of communicating about disease progression, for both HCPs and PwMS, and potential ways to optimise these discussions. PwMS' preferences and priorities regarding conversations about disease progression vary widely. While the majority want to have these conversations, some will be reluctant and/or emotionally unready. Communication therefore needs to be personalised, and HCPs should always be prepared to have such conversations in an appropriate and sensitive manner. Clinical information can be opaque for PwMS, so HCPs also need to use language that is clear, easily understandable, and patient-friendly. MS in the 21st Century is in the process of developing several resources and programmes to help improve disease progression communication between HCPs and PwMS.